Nail Discoloration

I have a Rat Terrier and a Toy fox Terrier both about 6 months old. My Rat Terrier has red colored nails right when the nails exit the paw. It's on all four paws and he doesn't really lick his feet. He has had his shots and we currently are having problems with Fleas. We changed Dog food to see if that would help and it hasn't. I have no idea what I might be and hoping it might be something like changing dog food again or because he digs at the wall......

[ne55]

hi

I would say it would be bruising under the nail from damage due to digging at the wall....
why does he dig at the wall?
Has he been doing this for a long time?

ne55